SLAP lesion type IX: case series and a review of literature

PURPOSE

A type IX SLAP (superior labrum anterior to posterior) lesion involves 360° of the glenohumeral labrum. Only rare reports have been published analyzing the risk factors of this lesion and the success of its arthroscopic management. The aim of our study is to evaluate predisposing factors that lead to SLAP IX and to assess the clinical outcome after arthroscopic treatment. Our treatment algorithm is also presented.

METHODS

We report on a series of six patients treated in our institution between January 2014 and January 2019 who underwent shoulder arthroscopy and were intraoperatively found to have a SLAP lesion type IX. Arthroscopic labral repair and biceps tenodesis were indicated in all patients. American Shoulder and Elbow Surgeons (ASES) Shoulder Score, Rowe Score and Constant Murley Shoulder Score (CS) were used for clinical evaluation. Patients were evaluated preoperatively and at 12 weeks, 1 year and 2 years postoperatively.

RESULTS

We analyzed six patients of which 83% were males (5/6 patients). The average age at the time of surgery was 37.16 (range 30-42 years). The dominant arm was affected in 50% of patients (3/6 patients). A significant postoperative improvement was seen in all six patients. 83% (5/6) of patients returned to their pre-injury activity level. Average values of all three measured scores show a significant increase comparing preoperative to postoperative period (P-value < 0.05). All patients were able to return to work.

CONCLUSIONS

The final diagnosis was established intraoperatively as 83% (5/6) of radiology reports differed from subsequent arthroscopic findings. The mechanism of injury in all our cases was high energy trauma with traction, arm in abduction or anteflexion. We observed great success with arthroscopic treatment as high percentage of our patients returned back to work and sports.

Arthroscopic repair of inferior glenoid labrum tears (Down Under lesions) produces similar outcomes to other glenoid tears

PURPOSE

Inferior glenoid labral tears are an uncommon but distinct shoulder injury. Only a small number of studies have reported outcomes following arthroscopic repair. The aim of the current study was to report minimum 2-year outcomes following inferior labral repair and to compare outcomes and risk factors associated with the injury to non-inferior labral tears. Whether preoperative MRI or MRA identified inferior labral tears was also assessed.

METHODS

A prospective study of 162 consecutive patients undergoing arthroscopic glenoid labral repair, excluding isolated superior labral tears, was conducted. Of the 130 patients available for follow-up, 18 (13.7%) had an inferior labral tear ("Down Under lesion"), the remainder had anterior, posterior or mixed anterior/posterior lesions that did not include the inferior pole. Mean follow-up time for the Down Under group was 44 months (SD 10, range 27-57), and 30 months (SD 14, range 4-60) for the non-Down Under group. Postoperative outcomes included the Oxford Shoulder Instability Score and recurrent instability. Associations between Down Under lesions and injury mechanism, instability at presentation, recurrent instability and family history were assessed with multivariable logistic regression. Preoperative MRI or MRA reports by radiologists were examined to determine if Down Under lesions were identified.

RESULTS

Oxford Shoulder Instability Scores indicated that most patients in both groups had little pain or shoulder problems postoperatively (average Oxford Score 41; 48 = no symptoms). Oxford Scores were not significantly different between the Down Under and non-Down Under groups. Four patients (22.2%) in the Down Under group had recurring symptoms (pain and instability) compared to 12 (10.6%) in the non-Down Under group; this difference was not statistically significant (adjusted OR 1.09, 95% CI 0.19,4.77). Family history of shoulder instability was positively associated with a Down Under lesion (adjusted OR 5.0, 95%CI 1.51,16.7). MRI or MRA identified 52.9% of Down Under lesions.

CONCLUSION

Down Under lesions were an infrequent type of glenoid labral injury, yet postoperative outcomes were similar to other labral tears. Patients with Down Under lesions had a significant risk factor due to family history of shoulder instability. MRI and MRA could not reliably identify Down Under lesions.

LEVEL OF EVIDENCE

Level III.

Biomechanical evaluation contribution of the acetabular labrum to hip stability

PURPOSE

Knowledge of the effect of hip pathologies on hip biomechanics is important to the understanding of the development of osteoarthritis, and the contribution of the labrum to hip joint stability has had limited study. The purpose of this study was to evaluate the effect of labral injury to stability of the femoral head in the acetabular socket.

METHODS

Ten cadaver hip specimens were tested using a robotic system under four different loading conditions: axial loading (80 N) along the femoral axis and axial loading (80 N) combined with either anterior, posterior or lateral loading (60 N). The hip states were examined were intact, with a 1.5 cm capsulotomy and with a 1 cm resection of the anterosuperior labrum.

RESULTS

At 30° of flexion, under axial load, the displacement of the hip with capsulotomy and labral resection (9.6 ± 2.5 mm) was significantly larger then the hip with capsulotomy alone (5.6 ± 4.1 mm, p = 0.005) and the intact hip (5.2 ± 3.8 mm, p = 0.005). Also, at 30° of flexion, the displacement under combined axial and anterior/posterior load was increased with capsulotomy and labral resection.

CONCLUSION

The acetabular labrum provides stability to the hip joint in response to a distraction force and combined distraction and translation forces. One centimetre of labral resection caused significant displacement ("wobbling" effect) of the femoral head within the acetabulum with normal range of motion. Successful labral repair could be crucial for restoration of the hip biomechanics and prevention of coxarthrosis.